Expanded prostate cancer index composite for clinical practice: development and validation of a practical health related quality of life instrument for use in the routine clinical care of patients with prostate cancer.

PURPOSE

Measuring the health related quality of life of patients with prostate cancer in routine clinical practice is hindered by the lack of instruments enabling efficient, real-time, point of care scoring of multiple health related quality of life domains. Thus, we developed an instrument for this purpose.

MATERIALS AND METHODS

The Expanded Prostate Cancer Index Composite for Clinical Practice is a 1-page, 16-item questionnaire that we constructed to measure urinary incontinence, urinary irritation, and the bowel, sexual and hormonal health related quality of life domains. We eliminated conceptually overlapping items from the 3-page Expanded Prostate Cancer Index Composite-26 and revised the questionnaire format to mirror the AUA symptom index, thereby enabling practitioners to calculate health related quality of life scores at the point of care. We administered the Expanded Prostate Cancer Index Composite for Clinical Practice to a new cohort of patients with prostate cancer in community based and academic oncology, radiation, and urology practices to evaluate instrument validity as well as ease of use in clinical practice.

RESULTS

A total of 175 treated and 132 untreated subjects with prostate cancer completed the Expanded Prostate Cancer Index Composite for Clinical Practice. The domain scores of the Expanded Prostate Cancer Index Composite for Clinical Practice correlated highly with the respective domain scores from longer versions of the Expanded Prostate Cancer Index Composite (r≥0.93 for all domains). The Expanded Prostate Cancer Index Composite for Clinical Practice showed high internal consistency (Cronbach's α 0.64-0.84) and sensitivity to prostate cancer treatment related effects (p<0.05 in each of 5 health related quality of life domains). Patients completed the Expanded Prostate Cancer Index Composite for Clinical Practice efficiently (96% in less than 10 minutes and with 11% missing items). It was deemed very convenient by clinicians in 87% of routine clinical encounters and clinicians accurately scored completed questionnaires 94% of the time.

CONCLUSIONS

The Expanded Prostate Cancer Index Composite for Clinical Practice is a valid instrument that enables patient reported, health related quality of life to be measured efficiently and accurately at the point of care, and thereby facilitates improved emphasis and management of patient reported outcomes.